public function mayOperate($sOperation, $oUser = false)
 {
     if ($oUser === false) {
         $oUser = Session::getSession()->getUser();
     }
     $bIsAllowed = false;
     if ($oUser && ($this->isNew() || $this->getCreatedBy() === $oUser->getId()) && SubscriberGroupMembershipPeer::mayOperateOnOwn($oUser, $this, $sOperation)) {
         $bIsAllowed = true;
     } else {
         if (SubscriberGroupMembershipPeer::mayOperateOn($oUser, $this, $sOperation)) {
             $bIsAllowed = true;
         }
     }
     FilterModule::getFilters()->handleSubscriberGroupMembershipOperationCheck($sOperation, $this, $oUser, array(&$bIsAllowed));
     return $bIsAllowed;
 }